How do I get javax.crypto classes such as javax.crypto.Cipher to work on a servlet with jboss?

Question

My application validates a license file in order for it to work. It does this by calling javax.crypto.Cipher.getInstance(\"DES\",\"SunJCE\") inorder to decipher the license key

Answer 1

There are a couple of possible issues that come in mind, it seems to be a problem with classpath when sun/oracle jvm try to authenticate provider jars

• check that all security jars are under the <jdk_home>/jre/lib/ext of the jvm that runs jboss (ie US_export_policy.jar, sunjce_provider.jar, local_policy.jar....)

• about US_export_policy.jar and local_policy.jar be sure to have downloaded the unrestricted version

• java.security file in <jdk_home>/jre/lib/security: be sure to have a line similar to security.provider.X=com.sun.crypto.provider.SunJCE where X is a number

• be sure that sunJCE provider jar is not in you WEB-INF/lib

Answer 2

I figured out what was wrong with my code. Earlier in the code for some reason someone did the following:

if (SunJCEinProviders) 
{
Security.removeProvider("SunJCE");
}   

int i = Security.insertProviderAt(new  com.sun.crypto.provider.SunJCE(),1);

So for some reason we were removing javas initial SunJCE provider then adding a new one and this new one was failing to be authenticated.